I think it was Dawkins who said: "evolution would be disproven if we found a rabbit fossile in" (whatever the geological period was) "and so far this has not happened."

Hasn't it? Or has it but expertise has guessed at other explanations?

[Quoting Talk Origins Article, link here] : Clifford Burdick, of course, once argued for "The Discovery of Human Skeletons in Cretaceous Formation" (Creation Research Society Quarterly, Vol. 10, Sept. 1973) or, as the skeletons were nicknamed, "Moab Man." Human skeletons found in rock from the Cretaceous era? According to the geologic time scale, not even humanity's earliest human-like ancestors appeared until well after the Cretaceous. However, this case turned into yet another instance in which creationists had to recant due to the evidence pointed out by mainstream scientists. For instance, a professor of anthropology examined the "Moab Man" skeletons as soon as they were first uncovered (when some ground was being bulldozed). The professor agreed that these were indeed human skeletons, but that they were just Indian skeletons that had been buried in a rock crevice, the surrounding rocks dating back to the Cretaceous, but not the buried skeletons, which were merely slid in between the rocks, and which were later covered by sand, etc.

OK. A man's skeleton was found in Cretaceous layers, but he is not reckoned as having lived in the Cretaceous because sandstone layers could have dissolved into sand and later solidified as sandstone around him. One argument used is:

The bones themselves were not fossilized and there had been no replacement of bone calcium by mineralization. They were soft, friable and partly decayed -- in short, of rather recent vintage, probably historic Paiute or Ute, or possibly of Euro-American origin, since no associated artifacts were found." Later, a femur from one of the skeletons was carbon dated to around 210 years ago +/- 70 years. A few other such skeletons have also been found -- the same story applies, as outlined above.

What about dino's recently found with intact soft tissues? What about dino's C14 dated way later than Jurassic, also recently? That was recently featured in Creation.org. But more in same vein:

One of Baugh's more famous claims, aside from the dinosaur tracks, is an alleged out of place artifact of an "18th century miner's hammer" found in million-year-old Ordovician rock (he has also claimed it is in Cretaceous rock) found in 1934 from London, Texas.[18][19] Baugh asserted this as evidence against scientifically known ways that rocks form.[18] However, laboratory tests discounted his claim about the hammer's being formed in the rock.[18][19] J.R. Cole wrote, "The stone concretion is real, and it looks impressive to someone unfamiliar with geological processes. How could a modern artifact be stuck in Ordovician rock? The answer is that the concretion itself is not Ordovician. Minerals in solution can harden around an intrusive object dropped in a crack or simply left on the ground if the source rock (in this case, reportedly Ordovician) is chemically soluble."[20]

Obviously it is possible that both the man in cretaceous layers and the hammer in ordovician laters London, Texas (not to be lightly confused with the capital of England, of United Kingdom and of British Commonwealth) are later.

But with this method it is not quite clear that if a rabbit from carbiniferous were found it would be accepted as genuine. In other words, the claim Dawkins (if it was he) makes is not necessarily as "easily falsifiable" as he claims.

Do we find a believably testified timescale herein? Just perhaps if you trust radiometric dating. But then it would seem that is as dependent in discovery of methods on the geological scale as C14's half life on previous dating of Pharao Joser's (? or someone, in the fourties at least) mummy. Not to mention that "erratic measurings" are discarded as erratic. But of course, a nice relative dating can be made if you have finds with two major layers: Cambrian never under Ediacaran, Ordovician never under either of before and so on up to Quaternary, but always and everywhere the reverse order: Ediacaran above nothing, Cambrian above Ediacaran, Ordovocian above Cambrian or Ediacaran (or both) in plenty of examples of at least two different major layers like these. Or if Quaternary were never found lower than five feet under ground, Jurassic always at least ten feet under it, and so on. But that is very much less likely, and apart from Grand Canyon (and maybe one other site in the Americas) I have found no claim about this. But, I look through the fossile digs in wikipedia, and I find very few sites "from more than one period."

I would like to have seen a graph showing all the possible superpositions of period layers and for each or most of them a list of places where they had been found in relevant order but also a list of places where purported reverse order has been explained otherwise, i e through rocks shifting position over time.